Little things like extra line breaks, unexpected tabs, and quotes out of place could cause it to not be recognized.
This line looks right:
$InsertQuery->bindColumn("calendar_events_shift_event_parent_id", "i", "".((isset($_GET["calendar_events_id"]))?$_GET["calendar_events_id"]:"") ."", "WA_DEFAULT");
This one doesn't:
$InsertQuery->bindColumn("calendar_events_end_time", "s", ((isset($_POST["end_time"]))?$_POST["end_time"]:""), "WA_DEFAULT");
it would probably be recognized with:
$InsertQuery->bindColumn("calendar_events_end_time", "s", "".((isset($_POST["end_time"]))?$_POST["end_time"]:"") ."", "WA_DEFAULT");
You would probably have to go through each line to match that syntax before it would be picked up by the UI.